Mold forming apparatus



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/H:S ATTORNEY Sept. 17, 1957 R. P. DAVIS MOLD FORMING APPARATUS OriginalFiled April 11, 1952 10 Sheets-Sheet 2 INVENTOR.

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,0!) 04 M/% Hi6 ATTORNEY Sept. 17, 1957 R. P. DAVIS MOLD FORMINGAPPARATUS Original Filed April 11, 1952 10 Sheets-Sheet s y l x M A YINVEAATOR. Hab l Dal/L's.

H15. ATTORNEY Sept. 17, 1957 R. P. DAVIS MOLD FORMING APPARATUS OriginalFiled April 11, 1952 10 Sheets-Sheet 4 INVENTOR. Eaob I. Dal/L's.

BY A v ATTOHJVEI P 17, 1957 R. P. DAVIS 2,806,262

MOLD FORMING APPARATUS Original Filed April 11, 1952 10 Sheets-Sheet 5IN V EN TOR.

HIS 477 012025 R. P. DAVIS MOLD FORMING APPARATUS Original Filed April11,- 1952 Sept. 17, 1957 10 Sheets-Sheet 6 O O O INVENTOR. P. Davis.

H15 HTTOHIVEY p 17, 1957 R. P. DAVIS 2,806,262

MOLD FORMING APPARATUS Original Filed April 11, 1952 10 Sheets-Sheet '7IN VEN TOR.

F y 9 R ga/1 P. Davis. BY

H18 moizzwy P 1957 R. P. DAVIS I 2,806,262

MOLD FORMING APPARATUS Original File d Ap ril 11, 1952 1o Sheets-Shet s1 70 55 o v m 'o I IV 0 ,L j \J INVENTOR.

H15 'ATWORNFY Sept. 17, 1957 R. P/DAVIS MOLD FORMING APPARATUS OriginalFiled April 11, 1952 10 Sheets-Sheet 9 INVENTOR. I. Dal/4's.

Eao/z BY HIS ATTOHAZ'Y Sept. 17, 1957 R. P. DAVI'S MOLD FORMINGAPPARATUS Original Filed April 11, 1952 10 Sheets-Sheet 1O INVENTOR. Ralh P. Dag/e15.

AZTTOHNFY United States Patent MOLD FORMING APPARATUS Ralph P. Davis,Squantum, Mass., assignor, by mesne assignments, to Link-Belt Company,Chicago, 111., a corporation of Illinois Original application April 11,1952, Serial No. 281,766, now Patent No. 2,769,217, dated November 6,1956. Divided and this application September 17, 1954, Serial No.456,845

12 Claims. (Cl. 22-3S) This application is a division of my copendingapplication Serial No. 281,766, filed April 11, 1952, now Patent No.2,769,217 issued November 6, 1956, and which is a continuation-in-partof my copending application Serial No. 186,199, filed September 22,1950, now Patent No. 2,659,431 issued November 30, 1954.

This invention relates to foundry mold forming apparatus and moreparticularly to apparatus for continuously producing baked shell-typemolds by a sequence of automatic mold forming operations.

The molds to be formed by operation of the apparatus herein disclosedare produced from a dry mixture of inorganic molding material such assand and a minor portion of plastic binder. The dry mixture is appliedto pattern means which have been preheated to a temperature sufficientlyhigh to cause the binder to soften and cement the particles of moldingmaterial together to thereby build up a shell of the desired thickness.After the mold forming material has remained on the pattern for a timesufficient to form the shell, the pattern is inverted to dump excessmolding material and then returned to initial position for passagethrough the curing oven portion of the apparatus. Upon leaving thecuring oven, the baked molds are moved by the apparatus to an unloadingstation where they are ejected from the patterns which then move througha preheating oven to the original loading station for further moldforming operations.

The component parts of a mold forming apparatus may be summarized asfollows: a

(a) Oven means divided into a preheating oven and a curing oven.

(b) A conveyer in the form of a turret with means on each turret arm forreceiving and supporting pattern means.

Mechanism for indexing the turret and pattern means from a loadingstation through the curing oven, an unloading station, the preheat oven,and back to the loading station.

(d) Mechanism for connecting a flask to the pattern means at the loadingstation.

(e) A movable hopper for loading mold forming material onto each patternmeans for retention by the flask at the loading station.

(f) Mechanism for inverting the flask and pattern means to dumpingposition at the loading station and returning them to initial position.

(g) Mold ejecting means operable on the mold for removing the same fromthe pattern means at the unloading station after passage through thecuring oven.

The apparatus of this invention is of particular advantage in formingmolds of the described shell-type in large quantities. Since the moldscan be set aside after completion and even stored for long periods oftime before being used in casting processes, the continuous productionfeature of the apparatus may be put to full use at any convenient time.The apparatus may be operated under the control of one person and is ofrelatively simple aseazez Patented Sept. 17,

ice

nature embodying uncomplicated parts which are durable and rugged asrequired in general foundry practice.

A principal object of the invention is to produce foundry molds byrelatively unskilled labor without detracting from the quality of themolds so produced.

Another object of the invention is to produce a shelltype mold ofimproved quality with a uniform density of mold forming materialthroughout the mold.

Another object of the invention is to continuously repeat the cycle ofmold producing operations with difierent patterns if desired or withlike patterns where high production rate of a specified type of mold isrequired.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawings wherein:

Fig. l is a general plan view of the molding apparatus in a somewhatschematic form;

- Fig. 2 is a longitudinal section taken on the line IIII of Fig. 1;

Fig. 3 is an enlarged plan View of a portion of the apparatus looking inthe direction indicated by the lines IIIIII in Fig. 2;

Fig. 4 is an elevation looking in the direction indicated by the linesIVIV in Fig. 3;

Fig. 5 is an enlarged cross-section taken on the line V--V in Fig. 3; p

' Fig. 6 is an end view of that portion of the apparatus shown in Fig. 3looking in the direction indicated by the lines VIVI in Fig. 3;

Fig. 7 is a fragmentary sectional view taken on the line VIIVII in Fig.1;

Fig. 8 is an enlarged fragmentary sectional view taken on the lineVlll-VIII of Fig. 2;

Fig. 9 is a fragmentary sectional view taken on the line IXIX of Fig. 8;

Fig. 10 is an enlarged fragmentary sectional view taken on the line XXof Fig. 1;

Fig. 11 is an elevation of an operating mechanism for a pair of gateswithin the container shown in Fig. 10;

Fig. 12 is an enlarged fragmentary sectional view taken on the lineXII-XII of Fig. 1;

Fig. 13 is a diagrammatic showing of the electrical control system forthe molding apparatus; and r Fig. 14 is a diagrammatic showing of thefluid pressure control system for the molding apparatus.

The various parts of the apparatus will now be described referring moreparticularly to the drawings.

The ovens As best shown in Figs. 1 and 2, a curing oven 10 of generallyarcuate form is provided with open ends 12 and 14 spaced respectivelyfrom adjacent open ends 16 and 18 of a generally arcuate preheat oven20. The ovens 10, 20 are mounted on suitable supports secured to afoundation 22 such as a concrete floor. An arcuate passageway 24 ofsubstantially rectangular cross-section is provided in the curing oven10 and lined with fire brick or other heat resistant material. Anopening 26 formed in the inner wall of the passage 24 extends throughoutthe length of the passage 24 and provides access to the interiorthereof. A similar passage 28 and opening (not shown) are formed in thepreheat oven 20. 7

Heating means for the ovens 1t), 20 take the form of a plurality of gasburners 30 (only one of which is shown) of tubular form located beneaththe passageways 24, 28 of the ovens 10 and 2') respectively which areprovided with ports 32 in their lower walls through which the flamesfrom the burners 30 may project. A baffle plate 34 is provided in eachof the ovens above the ports 32 to prevent direct impingement of theflames with articles passing through the interior of the ovens 1th and20. Each of the burners 30 is provided with a pilot burner 36 by meansof which ignition may be effected. The burners 39 are suppliedwith fuelfrom a source of gas supply through a manifold 38 connected thereto. Athermostat 40 regulates the supplyof gas to the burner 30 to control thetemperature of the curing oven 10 and a similar thermostat (not shown)controls the temperature of the preheat oven 20.

Conveyor r turret A conveyor or turret, designated generally by thereference numeral 42 is provided for clockwise rotary movement about itsvertical axis and includes a support 44 rotatably supported on thefoundation 22. The axis of the support 44 substantially coincides withthe axis of the ovens and 20 so that a plurality,'in this instanceeight, of radial supportv means or turret arms 46 are adapted formovement in sequence through the oven passageways 24, 28. ,Each of theturret arms 46 comprises an outer cylinder 48 supported at one 'endon ahead element 50 mounted on the support 44, each outer cylinder 48terminating at the opposite end shortof the wall of the ovens 10, 20.Rotatably mountedwithin each cylinder 48 is a shaft 52 which projectstherefrom a sufficient distance to enter the oven passageway .24, 28through the elongated openings in the side ,wallsithereof. Rotation ofthe turret is effected by .a mechanism which will be describedhereinafter.

Releasable detent means is provided for each shaft 52 for preventingrotation thereof about its horizontal axis. This means may be carried ona generally circular plate 54 carried by the support 44 in underlyingsupporting relation with the cylinders and'extending radially beyond theouter ends thereof. Since the detent means for each shaft 52 isidentical, description of one will sufflee to show the structure of all.As best shown in Fig. 12, the detent or spindle locking means maycomprise a pin 56 journaled for vertical slidable movement in a suitablehole formed in the plate 54 beneath the shaft 52. A collar 58 carried bythe pin 56 is engageable with the underface of the plate 54 to limitupward movement of the pin 56 and a spring 60 acting between the collar58 and a suitable bracket 62 biases the pin 56 to its uppermostposition. In such position, the pin 56 extends into a recess 64 formedin a collar 66 securely mounted on the shaft 52. When the end of the pin56 is positioned within the recess 64 rotation of the shaft 52 about itshorizontal axis is precluded. However, upon downward movement of the pin56 against the bias of the spring 60, the pin 56 is moved out of therecess 64 and the shaft 52 is freed for rotation about its horizontalcenter line. Downward movement of the pin 56 is effected by an operatingmember 68 carried on the lower end of the pin 56 and engageable byoperating means to be more fully described hereinafter.

The terminal end of each shaft 52 carries a frame mem-,

ber 70 adapted to receive a pattern plate 72 which is mounted thereonfor passage through the ovens 10 and 20. One of the pattern plates 72 isshown more clearly in Fig. 7 with ejector means in the form of springbiased pins 76 projecting therethrough. The pattern plates 72 may be allalike for producing similar molds or they may vary one from the otherwhere different molds are desired.

The zone between the ends 12, 16 of the ovens 10, 20 respectively istermed the loading station and'it is desirable to'position each patternplate accurately in a predetermined position when located therein. Tothis end, an indexing lock is provided and the same may comprise abifurcated locking element 51 slidably mounted in a suitable support 53extending from the foundation 22. The locking element is arranged to bemovable vertically relative to the shaft 52 and when in its uppermostposition, is adapted to straddle the shaft 52 to accurately set theangular position thereof. A fluid pressure motor .55 is carried by thesupport 53 and includesapistonrod 57 which is connected at one end tothe locking element 51 for moving the same into and out of engagementwith the shaft 52.

A shifting lever 59 is pivotally mounted on the support 53 with one endthereof extending beneath the plate 54 to be engageable with theoperating member 68 of each shaft locking device when the same movesinto the loading station with its corresponding shaft 52. The other endof the shifting lever 59 is connected to the locking element 51 throughthe linkage 61, 63 so that upward movement of the bifurcated lockingelement into locking position will move the shifting lever 59 in aclockwise direction thereby moving the operating element 68 against thebias of the spring 60 to release the shaft 52 for rotation about itshorizontal axis.

Mechanism for indexing-and rotating the turret The means employed forrotating the turret 42 is shown in Figs. 2, 8 and 9 as comprising anannular plate 78 connected to the support 44 by a plurality of radiallyextending brackets 80 and disposed in parallel underlying relation withthe plate 54. A plurality of pairs of radially extendingcircumferentially spaced track elements 82 are carried on the undersideof the plate 78. Each element 82 of said pairs is spaced from itsassociated element to thereby provide a radially extending groove ortrack adapted to receive a cam element or roller 84. A plurality, hereshown as three, of rollers 84 are circumferentially spaced and rotatablymounted on a circular plate 86 which is positioned with a portionthereof disposed beneath the plate 78. The plate 86 is secured to thevertical output shaft of a reduction gear 88 mounted on the foundation22 and connected to a suitable air motor 90. Supporting the free end-ofthe reduction gear shaft is an outboard bearing 92.

The spacing of the rollers 84 and the track elements 82 is such thatupon rotation of the plate 86 one of the rollers 84 will enter the spacebetween a pair of the elements 82 and will move therealong with asubstantially simple harmonic motion to effect rotation of the plate 78and accordingly rotation of the turret 42 with smooth acceleration anddeceleration despite the relatively large masses involved. The spacingof the rollers 84 and the elements 82 is also such that as one of therollers 84 is moving out of engagement with a pair of the elements 82,another of the rollers 84 is initially engaging an adjacent pair of theelements 82 so that the plate 86 is operatively connected to the plate78 at all times.

A control lever 94 is positioned adjacent the plate 86 to besequentially engaged by each of the rollers 84. Engagement of the lever94 by one of the rollers 84 is effective to terminate the supply ofmotive fluid to the motor and thereby stop rotation of the turret 42when the same is in a predetermined position. Initiation of the supplyof motive fluid to the motor 90 is under the control of separate meanswhich will be discussed more fully hereinafter.

Flask and operating means therefor The loading station is locatedbetween the ends 12, 16 of the ovens 10, 20 respectively and disposed atthe'loading station is a movable flask 96. The flask 96 comprises agenerally rectangular open frame with the top edge thereof'lying in aplane disposed at an acute angle to the plane which contains the bottomedge thereof. The flask 96 is provided with a cooling system comprisinga jacket 98 encompassingthe frame of theflask and adapted to provide apassage 'forthe flow of a suitable coolant. The flask 96 is mounted forvertical movement relative to the conveyor 42.and thus may be loweredonto a pattern plate positioned at the loading station; Means isprovided for clamping the flask'96 to the pattern plate and rotatingtheassembly of the flask 96 and pattern plate 7 2 about theaxisof-thesupporting shaft52.

.More particularly, the flask 96 is pivotally mounted be- ;tween thearmsof a bifurcated'element 100 which ,is secured to one end of a'hollowshaft 102. The hollow shaft 102 is rotatably journaled in a cylindricalbearing 104 which is securely mounted on a vertically movable cart iageindicated generally by the reference numeral 106. The carriage 106 isguidedin its vertical movement by a pair of elongated bearings 108secured to opposite sides thereof and slidably engaging a pair of fixedtracks 110, the tracks 110 being carried by a ridged framework 112supported on the foundation 22.

To effect vertical movement of the carriage 106, a suitable air motor114, which is mounted on the foundation 22, is connected thereto througha reduction gearing 116, crank 118 and link 120. The link 120 ispivotally connected to the carriage 106 at 121 so that rotation of thecrank 118 by the motor 114 will move the pivot point 121 in a generallyvertical path controlled by the coaction of the bearings 108 with thetracks 110. The tracks 110 are so arranged with respect to the indexlocking element 51 that the flask 96 is accurately aligned with thepattern 72 and correct contact therebetween is insured when the carriage106 is lowered.

When the flask 96 is lowered onto the pattern plate 72, these elementsare securely clamped together by means provided for this purpose. Thismeans takes the form of a block 122 provided with a beveled face 124-and secured to the frame member '70 which supports the pattern plate 72.A shaft 126 journaled within the hollow shaft 102 for slidable androtatable movement therein carries a dog 128 on one end thereof. The dog128 is provided with a beveled surface 130 which is engageable with thebeveled face 124 on the block 122 upon axial movement of the shaft 126.It will be apparent that engagement of the beveled surface 130 with thebeveled face 124 will produce a wedging action transmitted through theframe 70 and bifurcated element 100 to force the flask 96 and patternplate 72 firmly into engagement with each other.

To move the dog 128 into and out of engagement with the block 122,actuating means for imparting axial movement to the shaft 126 isprovided. This means is here shown as comprising a collar 132 carried bythe shaft 126 for axial movement therewith but being free to rotaterelative thereto. A bifurcated shifting lever 134, pivoted on thecarriage 106, is pivotally connected at its bifurcated end to the collar132. The lever 134 is pivotally connected at its other end to a fluidpressure motor or 1 power piston 136 which is also pivotally mounted onthe carriage 106. The motor 136 is adapted to move the shifting lever134 about its fixed pivot to impart axial movement to the shaft 126 andthereby move the dog 12% into and out of engagement with the block 122carried by the frame member 70.

In a preferred embodiment of the invention, the fluid pressure motor 136also controls the operation of a brake mechanism 138 adapted to hold thecarriage 106 in a predetermined position when the dog 128 is inengagement with the block 122. The brake mechanism comprises a firstbrake shoe 140 mounted on the frame 112 for engagement by a second brakeshoe 142 which is carried by a lever 144 pivoted on the carriage 106. Alink 146 is pivotaily connected at one end to the operating element ofthe power piston 136 and is provided at its other end with an elongatedslot 1.43 which slidably receives a pin 150 carried by the lever 144.

When the operating element of the power piston 136 is extended to holdthe dog 128 in engagement with the block 122 as shown in Fig. of thedrawings, the link 146 is so positioned that the edges of the slot 148exert no restraining forces on the pin 150. However, when the actuatingelement of the power piston 136 is positioned to hold the dog 128 out ofengagement with the block 1.22, the link 146 is so positioned that theedge of the slot 148 engages the pin 156 to hold the lever 144 in aposition maintaining the brake shoe 142 out of engage ment with thebrake shoe 140.

A spring 152 acts between the link 146 and the lever 144 to bias thelever 144 in a counterclockwise direction as viewed in Fig. 5 and urgethe brake shoe 142 toward the brake shoe 140. Thus, when the powerpiston 136 is positioned to clamp the flask 9 6 to the pattern plates72, the link 146 is positioned to permit the spring 152 to hold thebrake shoes 142, in engagement and a yieldable brake arrangement iseffected. It is to be noted however that the spring 152 is precludedfrom producing a braking effect when the dog 128 is out of engagementwith the block 122 since in such position of the parts, the edge of theslot 148 engages the pin to hold the brake shoes 140, 142 apart.

As hereinbefore pointed out, it is desirable that the assembly of theflask 96 and pattern plate 72 be adapted to be inverted to dump excessmolding material from the flask 96. Motor means is provided forperforming this function and the same is here shown as a fluid pressureoperated motor 154 mounted on the carriage 106 and connected to areduction gearing 156 which is provided with an output shaft 153disposed in substantial alignment with the shaft 126. The shaft 158 isconnected to the shaft 126 by any suitable coupling 160 which willpermit axial shifting of the shaft 126 relative to the shaft 158 whilemaintaining a torque transmitting relation therebetween. As this type ofcoupling is well known in the art, further description thereof is deemedunnecessary.

With the arrangement disclosed, torque produced by the air mot-or 154will be transmitted through the reduction gear 156, shaft 158, coupling16h, shaft 126, dog 128, and block 122 to the frame member 7 0 to effectrotation of the assembly of the flask 96, pattern plate '72 and framemember 70 about the axis of the supporting shaft 52. It will be apparentthat with such an arrangement, the axis of the shaft 126 mustnecessarily be substantially coincident with the axis of the shaft 52during rotation of the flask and pattern assembly.

Hopper Positioned between the ends 12, 16 of the ovens 10, 20respectively in what has been termed the loading station is a hopper forthe molding material designated generally by the reference numeral 162.An elevator 164 is supported on the foundation 22 and conveys themolding material to a chute 166 which in turn conducts the material intoa movable container 168.

As best shown in Figs. 2 and 10, the container 168 is pivoted at itsupper end at 170 and is adapted to engage, when in the verticalposition, the upper edge of the flask 96. Fluid pressure motor meanshere shown as a power piston 172 is connected to the container 168 tomove the same about its pivot 170 to the position shown in broken linesin Fig. 2.

Positioned within the container 168 near the lower end thereof is a pairof gates 174. Each of the gates 174 is carried by a shaft 176 journaledin suitable bearings (not shown) carried by the wall of the container168. One end of each shaft 176 is provided with a pinion 178, thepinions 17 8 respectively meshing with a pair of racks 18%) carried onopposite ends of a piston rod 182. Limited axial movement is imparted tothe rod 182 by a suitable fluid motor 184 mounted on the wall of thecontainer 168. Upon such axial movement of the rod 182, the shafts 1'76are rotated to move the gates 174 between open and closed position, theopen position of the gates 174 being shown in broken lines in Fig. 10.

Positioned within the container 168 beneath the gates 1'74, is a screen186 adapted to be vibrated by a suitable fluid motor 138. Also withinthe container 168 but above the gates 174, is a mechanism fordischarging a predetermined quantity of mold forming material upon thegates 174 when the same are in closed position. anism may comprise agenerally funnel-shaped wall 196 with the larger end thereof secured tothe walls of the container 163 and the smaller end thereof directeddownwardly toward the gates 174.

Such mech- A shaft 192 extends through the wall 190 and the outer endsthereof pivotally support a pair of plates 194 each of which is in theshape of a segment of a circle with the arcuate edge thereof remote fromthe shaft 192. An arcuate plate 196 is secured to the arcuate edges ofthe plates 194 and underlies the open end of the funnelshaped wall 190so that when the container 168 is in the vertical position as shown inFig. 10, the arcuate plate 196 will effectively close the port definedby the smaller end of the funnel-shaped wall 190 and prevent flow ofmold forming material therethrough. However, when the container 168 ismoved out of the vertical position to the broken line position shown inFig. 2, the assembly of the sector shaped plates 194 and arcuate plate196 will pivot about the shaft 192 under the influence of gravity tothereby open the port defined by the smaller end of the funnel-shapedwall 190 and permit mold forming material to flow therethrough onto thegates 174.

Upon return of the container 162 to the vertical position, the arcuateplate 196 will again assume the position shown in Fig. under theinfluence of gravity and the supply of mold forming material to thespace above the gates 174 will be cut off. It will thus be apparent thatmovement of the container 168 out of engagement with the flask 96 andsubsequent return movement thereof into engagement with the flask 96will be effective to deposit a predetermined quantity of mold formingmaterial upon the gates 174.

When the gates 174 are moved to open position by the fluid pressuremotor 184, such predetermined quantity of mold forming material willdrop as a slug onto the vibrating screen 186 which will break the sameup into a shower of finely divided particles. It has been found thatsuch a shower of finely divided falling particles will produce a mold ofsuperior quality since the small particles do not pyramid on flatpattern surfaces to deflect other particles and leave voids adjacentvertical pattern surfaces. With a shower of fine particles, the moldingmaterial packs very closely around all vertical and inclined patternsurfaces.

Mold ejecting means Positioned between the end 14 of the oven 10 and theend 18 of the oven in what may be termed the unloading station, is themold ejecting mechanism designated generally by the reference numeral198. The ejecting mechanism 198 is shown in Figs. 1 and 7 as comprisinga cylindrical housing 200 supported on a plurality of leg members 202from a base 204 which is secured to the foundation 22. The housing 200contains an axially movable rodrnember 206 carrying an ejecting plate263 beyond the end of the housing 200. Movement of the rod member 206 iseffected by a fluid motor device such as an air motor 210 which ismounted between the base 204 and the rod member 206 for this purpose.Movement of the plate 298 toward and away from the housing 200 willserve to operate the ejector pins 76 of the pattern plate 72 and removethe mold formed thereon after passage through the curing oven 10.

Control system Referring to Figs. 13 and 14 showing the controlmechanism for accomplishing the various functions of the hereinbeforedescribed apparatus, it will be observed that both fluid pressure andelectrical energy are utilized. The details of the fluid pressure andelectrical control systems will be brought out in a description of theoperation of the apparatus which follows.

Operation In generalterms, the steps which comprise the operation of theapparatus of this invention are as follows:

1. A preheated pattern 72 is positioned at the loading station and theflask 96 is lowered onto the same while the container :168 moves intoengagement with the flask 96.

"8 2. The gates 174 open and .perrnit a quantity of inorganic moldingmaterial to be dropped onto the pattern plate to be retained by theflask.

3. The container 168 swings away from the flask 96 and the assembly ofthe pattern plate 72 and flask 96 is rotated to dump excess mold formingmaterial therefrom. The assembly of the pattern plate 72 and flask 96 isthen rotated to its original position and the' flask 96 is raised out ofengagement with the pattern plate 72.

4. The turret 42 is rotated or indexed to move the pattern plate withthe mold forming material thereon into the curing oven 10 whilesimultaneously moving a preheated pattern plate out of the preheat oven20 to the loading station.

5. The above steps are repeated with each indexing step moving a patternplate with a cured mold thereon out of the curing oven 10 to theunloading station where the finished mold is ejected therefrom. Eachindexing step also moves a pattern out of the preheat oven 20 to theloading station beneath the flask 96.

The detailed operation of the apparatus is as follows:

Assuming that a pattern plate 72 is positioned in the loading stationbeneath the flask 96 which is in its raised position and referring moreparticularly to Figs. 13 and 14, operation of the apparatus is initiatedby the operators momentarily closing a switch 21.. which energizes thecoil 214 of a sequence relay 216 through a circuit which may be tracedas follows: from line wire L2 through wire 218, wire 220, switch 212,wire 222, wire 224, coil 214, and Wire 226 to line wire L1. Energizationof coil 214 closes a first switch A of a sequence relay 216 whichcompletes a circuit which may be traced as follows: from line wire L2,through wire 228, switch A, wire 230, switch 232, wire 234, wire 236,coil 238, and wire 240 to line Wire L1. Coil 238 is operativelyassociated with a two- Way control valve 242 adapted to control thesupply of motive fluid to the fluid pressure motor 114 which operatesthe carriage 1G6. Energization of coil 238 upon completion of theabove-described circuit will cause the valve 242 to admit motive fluidto the motor 114 causing the same to apply power to the carriage 106through the reduction gear 116, crank 118, and link to move the carriage106 and associated flask 96 down to the position shown in Figs. 2, 4, 5and 6. The flask 96 is now in engagement with the pattern plate 72.

Closing of the switch A also completes a circuit through the primary ofthe transformer 244, which circuit may be traced as follows: from linewire L2, through wire 228, switch A, wire 239, switch 232, wire 234,wire 246, primary winding of transformer 244, wire 248, and wire 240 toline wire L1. Energization of the primary winding of the transformer 244energizes the secondary winding of said transformer which in turnenergizes a coil 250 through wire 252. Coil 250 is operativelyassociated with a two-way valve 254 adapted to control the supply ofmotive fluid to the fluid pressure motor 172 which moves the container168 about its pivot 170.

When the coil 250 is energized, the valve 254 is actuated to supplymotive fluid to the fluid pressure motor 172 to swing the container 168about its pivot 170 to its vertical position wherein the lower portionengages the upper edge of the flask 96. The switch 232 is arranged to beactuated by the flask 96 when the same moves to its lower position andwhen the flask 96 so moves, the switch 232 is positioned to complete acircuit which may be traced as follows: from line Wire L2 through wire228, switch A, wire 230, switch 232, wire 256, primary winding of atransformer 258, and Wire 240 to line wire L1.

When the primary winding of the transformer 258 is energized, thesecondary winding of said transformer is also energized and serves toenergize a coil 260 through wires 262 and 264. The coil 260 isoperatively associated with a four-way valve 266 adapted to control thesupply of motive fluid t0 the fluid pressure motor 136 which actuatesthe dog 128. When the coil 260 is energized, the valve 266 admits motivefluid to the pressure motor 136 to cause the same to rotate the shiftingarm 134 in a clockwise direction as viewed in Fig. to thereby shift theshaft 126 and attached dog 128 to the right as viewed in Fig. 5. Suchmovement of the dog 128 causes the beveled face 130 thereof to engagethe beveled face 124 of the block 122 and securely clamp the frame 70,pattern plate 72 and flask 96 together.

A switch 268 is positioned to be closed by the container 168 when thesame moves to the vertical position as shown in Fig. l of the drawings.Thus, movement of the container 168 into engagement with the flask 96closes the switch 268 and connects a pair of coils 270, 272 in parallelbetween the secondary of transformer 258 and ground through a wire 274.The coil 270 is operatively associated with a four-way valve 276 adaptedto control the supply of motive fluid to the fluid pressure motor 184which actuates the gates 174. When the coil 270 is energized, the valve276 is moved to a position wherein fluid under pressure is supplied tothe pressure motor 184 to open the gates 174 permitting molding materialthereon to drop onto the screen 186.

The coil 272 is operatively associated with a valve 278 adapted tocontrol the supply of motive fluid to the fluid pressure motor 188 forvibrating the screen 186 and when the coil 272 is energized, the valve278 is positioned to admit motive fluid to the motor 188. The moldforming material dropped through the gates 174 is thus broken up intofinely divided particles by the vibrating screen 186 and falls in suchfinely divided form onto the pattern plate '72. Since the pattern plate72 has been preheated in the preheat oven 20 to a temperaturesufliciently high to eflect fusion of the binder in the mold formingmaterial, the binder softens and cements together the particles ofmolding material thereby building up a shell contiguous the patternplate.

A switch 280 is positioned to be momentarily moved to closed positionwhen the gates 174 move between open and closed positions. Thus, whenthe gates 174 move to open position, the switch 280 is momentarilyclosed connecting a time delay mechanism 282 across line wires L1, L2through a circuit which may be traced as follows: from line wire L1through wire 240, wire 284, switch 280, wire 285, timer 282 and wire 286to line wire L2. After a predetermined time delay, the timer 282connects the primary winding of a transformer 288 across line wires L1,L2 through a circuit which may be traced as follows: from line wire L1through wire 240, wire 290, primary winding of transformer 288, wire292, timer 282, and wire 286 to line wire L2.

A pair of coils 294, 296 are each connected to ground and are connectedin parallel to the secondary winding of the transformer 288 through awire 298. The secondary winding of the transformer 288 is also groundedso that upon energization of the primary winding of said transformer,the coils 294 and 296 are energized. The coil 294 is operativelyassociated with the valve 2'76 and when energized is effective toposition the valve 276 to supply motive fluid to the fluid pressuremotor 184 in such a way as to cause the same to close the gates 174. Thecoil 296 is operatively associated with the valve 278 and when energizedis effective to position the valve 278 to terminate the supply of motivefluid to the vibrator motor 188 thereby terminating the vibrating motionof the screen 186. It will thus be apparent that the gates 174 areclosed and the vibrating motion of the screen 186 is terminated at theend of a predetermined time interval initiated by the opening of thegates 174.

A switch 300 is positioned to be closed by the gates 174 when the sameare moved to closed position and when closed connects a coil 302 withthe secondary winding of transformer 288 through wire 298. The coil 382is connected to ground and will therefore be energized upon energizationof the secondary winding of the trans- 10 former 288 when the switch 300is closed. As the gates 174 move to closed position, the switch 280 isonce again momentarily closed to initiate operation of the timer 282.

After a predetermined time interval, the timer 282 once again connectsthe primary winding of the transformer 288 across line wires L1, L2through the circuit previously traced. The coil 302 is then energized.The coil 302 is operatively associated with the valve 254 and whenenergized is efiective to position the valve 254 to admit fluid underpressure to the fluid pressure motor 172 in such a manner that the motor172 will move the container 168 about its pivot 170 and out ofengagement with the flask 96. As the container 168 moves away from theflask 96, the plate 196 moves relative to the tapered wall 190 to openthe port defined by the smaller end thereof and permit mold formingmaterial to flow onto the closed gates 174.

A switch 304 is positioned to be momentarily closed by the container 168as the same swings away from its vertical position over the flask 96.Closing of the switch 304 completes a circuit for energizing the coil214 of the sequence relay 216 which circuit may be traced as follows:from line wire L2 through wire 218, wire 306, switch 304, Wire 308, wire224, coil 214, and wire 226 to line wire L1. Such momentary energizationof the coil 214 is effective to open the switch A of the sequence relay216 and close a second switch B thereof.

Closing of the switch B completes a circuit through a coil 310 asfollows: from line wire L1 through wire 312, wire 314, coil 310, wire316, switch B, and wire 318 to line wire L2. The coil 310 is operativelyassociated with a two-way valve 320 adapted to control the supply ofmotive fluid to the fluid pressure motor 154 for eifect ing rotation ofthe flask and pattern plate assembly.

When the coil 310 is energized, the valve 320 is positioned to admitmotive fluid to the fluid pressure motor 154 for causing rotationthereof in one direction thereby dumping excess mold forming materialfrom the flask. As hereinbefore set forth, torque is transmitted fromthe fluid pressure motor 154 to the flask 96 through the re duction gear156, output shaft 158, coupling 160, shaft 126, and dog 128.

When the flask 96 has rotated through approximately a switch 322 isoperatively engaged thereby and momentarily closed to complete a circuitthrough the coil 214 of the sequence relay 216 as follows: from linewire L2 through wire 218, wire 324, switch 322, wire 326, wire 224, coil214, and wire 226 to line wire L1. Such energization of the coil 214 ofthe sequence relay 216 is effective to open the switch B and close athird switch C thereof.

Opening of the switch B of sequence relay 216 is effective to deenergizecoil 310 thereby cutting off the supply of motive fluid to the fluidpressure motor 154 and terminating rotation of the flask 96. When theswitch C of the sequence relay 216 closes, a coil 328 is energizedthrough a circuit which may be traced as follows: from line wire L1through wire 312, wire 330, switch 332, wire 334, coil 328, wire 336,switch C, and wire 338 to line wire L2. The coil 328 is operativelyassociated with the valve 328 and when energized is effective toposition the valve 328 to supply motive fluid to the fluid pressuremotor 154 in such a way that the rotation thereof is reversed and theflask is rotated to its initial position through the mechanismhereinbefore described.

Rotation of the flask 96 is terminated when the same returns to itsinitial position by operative engagement of the flask 96 in suchposition with the switch 332, such engagement being effective to movethe switch 332 to break the previously traced energizing circuit for thecoil 328. Deenergization of the coil 328 causes the valve 328 toterminate motive fluid supply to the fluid pressure motor 154 andpreclude further rotation of the flask 96.

Operative engagement of the switch 332 by the flask 96 is not onlyeffective to deenergize the coil 328 but also 11 moves the switch 332 toa position wherein a circuit for energizing the primary winding of atransformer 340 is completed. This circuit may be traced as'foll'ows:from line wire L1 through wire 312, Wire 330, switch 332, wire 342,primary winding of transformer 340, wire 344, wire 336, switch C ofsequence relay 216, and wire 338 to line wire L2. One terminal of thesecondary winding of the transformer 340 is connected to ground and theother end thereof is connected to a coil 346 which in turn is groundedso that energization of the secondary winding of the transformer 340effects energization of the coil 346.

The coil 346 is operatively associated with the valve 266 and whenenergized is eflective to position the valve 266 to admit motive fluidto the fluid pressure motor 136 in such a manner that the motor 136 willmove the shifting arm 134 in a counterclockwise direction as viewed inFig. 5. The shaft 126 is thus shifted axially to the left as viewed inFig. and the dog 128 carried thereby is moved out of engagement with theblock 122 to free the flask 96 for movement out of engagement with thepattern plate 72. I

A switch 348 is arranged to be momentarily closed by the dog shiftingmechanism when the same moves the dog 128 out of engagement with theblock 122. Closing of the switch 348 momentarily energizes the coil 214of the sequence relay 216 through the following circuit: from line wireL2 through wire 218, wire 350, switch 348, wire 352, wire 224, coil 214,and wire 226 to line wire L1. Such momentary energization of coil 214 iseffective to open the switch C of sequence relay 216 and close a fourthswitch D thereof thereby energizing a coil 354 through the followingcircuit: from line wire L2, through wire 356, switch D, wire 35%, aswitch 360, wire 362, coil 354, and wire 240 to line wire L1.

The coil 354 is operatively associated with the valve 242 and whenenergized is effective to position the valve 242 to admit motive fluidto the fluid pressure motor 114 to cause rotation of the same in adirection opposite to that previously described. Such rotation of thepressure motor 114 is effective to rotate the crank 118 in a clockwisedirection as viewed in Fig. 5 to move the carriage 106 upward therebymoving the flask 96 out of engagement with the pattern plate 72.

When the flask 96 has moved through a predetermined distance, the switch360 is operatively engaged thereby and moved to an open position tobreak the previously traced energizing circuit for the coil 354 therebypermitting the valve 242 to move to closed position and termimate thesupply of motive fluid to the fluid pressure motor 114.

The loading operation is nOW' complete and indexing of the turret 42 tomove the loaded pattern plate into the curing oven must be performed. Toinitiate the indexing operation, the operator momentarily closes aswitch 364 which completes a circuit which may be traced as follows:from ground to one terminal of the secondary winding of a transformer366 through the secondary winding of the transformer 366, wire 368,switch 364, wire 370, and a coil 372 to ground. The primary winding ofthe transformer 366 is connected across line wires L1, L2 by wires 312,374.

Thus, closing of the switch 364 is effective to energize the coil 372.The coil 372 is operatively associated with a four-way valve 376 adaptedto control the supply of motive fluid to the fluid pressure motor 90 andthe fluid pressure motor 55. When the coil 372 is energized, the valve376 is positioned to admit motive fluid to the fluid pressure motor 55in such a manner as to cause the same to lower the bifurcated indexlocking element 51 thereby freeing the turret 42 and at the same timemoving the shifting lever 59 in a counterclockwise direction as viewedin Fig. 12. Such movement of the lever 59 will release thepin 56 formovement under the bias of the spring 60 into engagement with the collar66 for preventing rotation of the shaft 52 about its horizontal axis.

When the valve 376 is so positioned, fluid under pressure is alsoadmitted to the fluid pressure motor for causing the same to rotate theplate 86 through the reduction gear 88 to thereby rotate the turret 42'about its support 44. When the fluid pressure motor 90 has rotated theturret 42 through an angle suflicient to bring a second pattern plateinto alignment with the flask 96, one of the rolls 84 carried on theplate 86 contacts the control lever 94 to momentarily close a switch378. Closing of the switch 378 is effective to connect a coil 380 acrossthe secondary of the transformer 366 through a circuit which may betraced as follows: from the upper terminal of the secondary winding ofthe transformer 366 through wire 363; wire 382, switch 378, wire 384,and coil 380 to ground.

The coil 380 is operatively associated with the valve 376 and whenenergized is effective to position the valve 376 to terminate the supplyof motive fluid to the fluid pressure motor 90 and thereby terminaterotation of the turret 42. When the coil 380 is energized, the valve 376is also positioned to admit motive fluid to the fluid pressure motor 55in such a manner that the indexing locking element 51 is moved upward tostraddle a second shaft 52 and the shifting lever 59 is moved in aclockwise direction as viewed in Fig. 12 to move the pin 56 out ofengagement with the collar 66 on said second shaft 52 which is nowaligned with the flask at the loading station. The apparatus is nowready for repetition of the loading operation which, as hereinbeforedescribed, is initiated by the closing of the switch 212 by theoperator.

It will be understood that as each pattern is indexed out of the preheatoven 20 to the loading station, a loaded pattern plate is indexed fromthe loading station into the curing oven 10 and a pattern plate with acured mold thereon is indexed to the ejection or unloading station wherethe finished mold is ejected from the pattern plate by the ejector pins76 actuated by the fluid pressure motor 210. Supply of motive fluid tothe motor 210 is under the control of a manually operated valve 386. Itis also to be understood that the described indexing operation iseffective to move the pattern plates from the ejection station throughthe preheat oven 20 tothe loading station.

The operation is thus continuous and semi-automatic under control of asingle operator since, while an ejecting operation is being conducted,the loading, dumping, baking and preheating operations are beingperformed at the other stations. It will be apparent that many changesmay be made in the details of construction and arrangements of parts andthat certain phases of the cycle may be rearranged or omitted withoutdeparting from the scope of the invention as defined in the appendedclaims.

It is claimed and desired to secure by Letters Patent:

1. In a mold forming apparatus, the combination of rotatable patternmeans, a hopper for mold forming material adapted for movement between aplurality of positions, means cooperable with said hopper and saidpattern means and defining a passage providing communication betweensaid hopper and said pattern means in one of said positions, meanscooperable with said hopper for discharging a predetermined quantity ofmold forming material onto said pattern means through said passage, andmeans operable in response to movement of said hopper to another of saidpositions for inverting said pattern means to thereby dump excess moldforming material therefrom.

2. In a mold forming apparatus, the combination of pattern means, flaskmeans movable into engagement with said pattern means, a hopper for moldforming material adapted for movement between a plurality of positions,means responsive to movement of said flask means into engagement withsaid pattern means for moving-said hopper into alignment with said flaskmeans, means cooperable with said hopper for discharging a predeterminedquantity of mold forming material onto said pattern means for retentionby said flask means, means for moving said hopp'er to another of saidpositions, and means responsive to movement of said hopper to said otherposition for inverting the assembly of said flask means and said patternmeans for dumping excess mold forming material therefrom and thereafterreturning said assembly to its initial position.

3. A mold forming apparatus as claimed in claim 2 wherein meansresponsive to movement of said assembly to said initial position isprovided for moving said flask means out of engagement with said patternmeans.

4. In a mold forming apparatus, the combination of rotatable patternmeans, a hopper for mold forming material adapted for movement between aplurality of positions, movable flask means cooperable with said hopperand said pattern means and defining a passage providing communicationbetween said hopper and said pattern means in one of said positions,means cooperable with said hopper for discharging a predeterminedquantity of mold forming material onto said pattern means through saidpassage, means for inverting said pattern means to thereby dump excessmold forming material therefrom, a plurality of motor devicesoperatively associated with said hopper and said means respectively foractuating the same, and electrically operable means for controlling saidmotor devices and causing sequential operation thereof.

5. The combination claimed in claim 4 wherein said motor devices arefluid pressure operated, said electrically operable means controllingthe supply of motive fluid thereto.

6. In a mold forming apparatus, the combination of pattern means,movable flask means, motor means for moving said flask means intoengagement with said pattern means and returning the same to initialposition, a movable hopper for mold forming material, motor means formoving said hopper into alignment with said flask means and returningthe same to initial position, means cooperable with said hopper fordischarging a predetermined quantity of mold forming material onto saidpattern means for retention by said flask means, motor means foractuating said last named means, motor means for inverting the assemblyof said flask means and said pattern means while the same are inengagement for dumping excess mold forming material therefrom andthereafter returning said assembly to its initial position, andelectrically operable means for controlling the operation of said motormeans and causing sequential operation thereof.

7. A mold forming apparatus as claimed in claim 6 wherein said motormeans are actuated by fluid pressure, and a plurality of valvesrespectively controlling the supply of motive fluid to said motor means,said electrically operable means controlling the operation of saidvalves.

8. In a shell mold forming machine, heated pattern means, flask meansmovable into operative engagement with said pattern means, a hopper formold forming material movable into operative relation with said flaskmeans, means cooperable with said hopper for discharg ing a quantity ofsaid material onto said pattern means for retention by said flask means,means operable for moving said hopper out of said operative relationupon completion of said discharging operation; and means responsive tooperation of the last said means for causing said flask means to beemptied of mold forming material in excess of that adhering to saidpattern means to form a shell mold.

9. In a shell mold forming machine as claimed in claim 8 wherein meansresponsive to said flask emptying means is provided for separating saidflask and pattern means.

10. In a shell mold forming machine, heated pattern means movable in apredetermined path to a loading station, flask means positioned at saidloading station, means for moving said flask means into and out ofoperative engagement with said pattern means, a hopper positioned atsaid loading station and containing mold forming material, means formoving said hopper into and out of operative relation with said flaskmeans, measuring means in said hopper for a predetermined quantity ofmold forming material, gate means controlling an outlet for said hopperand operable for discharging said quantity of mold forming material ontosaid pattern means for retention by said flask means, means operable forfirst moving said hopper out of said operative relation and thereafterseparating said flask and said pattern means, and means for actuatingsaid last means in sequence of predetermined periods sufficient to causesaid heated pattern means to form a shell mold.

11. In a shell mold forming machine as claimed in claim 10 wherein meansare provided responsive to said hopper moving means for causing saidflask means to be emptied of mold forming material in excess of thatadhering to said pattern means.

12. In a shell mold forming machine, heated pattern means movable in apredetermined path to a loading station, flask means positioned at saidloading station, means for moving said flash means into and out ofoperative engagement with said pattern means, a hopper positioned atsaid loading station and containing mold forming material, means formoving said hopper into and out of operative relation with said flaskmeans, said hopper being in substantial axial alignment with saidpattern means and said flask means in said operative relation, measuringmeans in said hopper for a predetermined quantity of mold formingmaterial, and gate means controlling an outlet for said hopper andoperable for discharging said quantity of mold forming material ontosaid pattern means :for retention by said flask means.

References Cited in the file of this patent UNITED STATES PATENTS718,442 Field Jan. 13, 1903 1,595,600 Demmler Aug. 10, 1926 2,412,425Rawson Dec. 10, 1946 2,542,243 Gedris Feb. 10, 1951

